fix: remove redundant url.strip() check in download_video

not url already catches empty string, making url.strip() == ''
the 3rd useless condition.

youtube_cli/main.py

@@ -754,7 +754,7 @@ class YouTubeCLI:
         """Download a video using yt-dlp with progress bar."""
 
         # Validate URL before proceeding
-        if not url or not isinstance(url, str) or url.strip() == "":
+        if not url or not isinstance(url, str):
             logger.error("Invalid or empty video URL provided.")
             return False